I saw it on the early to mid 80s on satellite. I only remember a couple of scenes. By the way, it isn't Zombie Lake.

This guy attacks this woman who is able to drive him away. He goes to wash off the blood of his injuries in a nearby pond. Suddenly, these pale white arms grab the guy and drag him underwater. Later, the woman goes to the same pond the washes off but without the arms dragging her to her death.

"Shockwaves" has some scenes that are very close to this, so checking it out would be a good suggestion - but a scene exactly as mentioned is not present. There is one very close at about an hour in. I skimmed the movie at 20X to check.